# TODO + 数据拼接 str、list、tuple
# str
print('hello' + ' world')
# list
l1 = [1, 2]
l2 = [4, 5]
l3 = l1 + l2
print(l3)
# tuple
print((1, 2) + (3, 4))

# TODO * 重复, 只能和整数相乘 str、list、tuple
# str
print('--' * 3)
# list
print([1, 2] * 3)
# tuple
print((1, 2) * 2)

print('--' * 20)
# TODO in 判断元素在容器中
# 语法: item in container
# str
print('a' in 'abc')
# list
print('a' in ['a', 'b'])
# tuple
print('a' in ('a', ))
# dict
print('a' in {'a':1, 'b':2})
print(1 in {'a':1, 'b':2}.values())

# TODO not in 判断元素不再容器中
# str
print('a' not in 'abc')  # False
print('d' not in 'abc')  # True
